Selection of enzymatic electrochemical sensor for determination of L-asorbic acid

master's thesis

• Title: Odabir enzimskog elektrokemijskog senzora za određivanje L-askorbinske kiseline
• Author: Nenad Bratković
• Mentor: Željka Filipovic Kovacevic (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Analytical Chemistry); Zagreb
• Defense date and country: 2007-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom radu primjenjene su elektrokemijske analitičke tehnike za određivanje L-askorbinske kiseline u prirodnim uzorcima i prehrambenim proizvodima. Korištene elektrokemijske analitičke tehnike su amperometrijske prirode, za ciju su izvedbu načinjene enzimske modificirane elektrode imobilizacijom enzima na elektroaktivnoj površini elektroda. Za pripremu enzimskog i tkivnog elektrokemijskog senzora za mjerenja u: standardnoj elektrokemijskoj ćeliji, protočnoj ćeliji i u ćeliji s protočnim ubrizgavanjem (FIA), primjenjena su tri enzima: tirozinaza, polifenol-oksidaza i askorbat-oksidaza. Kao referentna metoda korištena je spektroskopska metoda. U usporedbi biosenzora, najpreciznije i najosjetljivije rezultate pokazuje enzimski biosenzor tirozinaze, a u usporedbi primjenjenih analitičkih tehnika, najbržu i optimalno izvedivu tehniku predstavlja analiza u ćeliji s protočnim ubrizgavanjem (FIA).

Abstract (english)

In this paper electrochemical analytical techniques have been studied for determination of L-ascorbic acid in natural samples and dietary products. Applied electrochemical analytical methods are amperometric by nature and for their application the enzimatically modified electrodes have been developped by enzyme imobilization on the electroactive surface of electrodes. For preparation of enzyme- and tissue- electrochemical biosensor for measurements in: standard electrochemical cell, flow cell and in flow-injection cell (FIA), three enzymes have been applied: tyrosinase, polyphenol-oxidase and ascorbate-oxidase. As a referential analytical method spectroscopy has been applied. In comparison of biosensors, the tyrosinase enzyme-biosensor provides the most accurate and the most sensitive results, while in comparison of the applied analytical techniques, flow-injection analysis (FIA) represents the fastest and the optimal performable analytical technique.

• Keywords: amperometrija; enzimski biosenzor; L-askorbinska kiselina; spektroskopija; tkivni biosenzor
• Keywords (english): Amperometry; enzymatic biosensor; L-ascorbic acid; spectroscopy; tissue biosen
• Language: croatian
• URN:NBN: urn:nbn:hr:159:108469
• Study programme: Title: Prehrambena tehnologija; smjerovi: Nutricionizam; Study programme type: sveučilišni; Study level: dodiplomski; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer nutricionizam (diplomirani inženjer prehrambene tehnologije; smjer nutricionizam)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Restricted access
• Created on: 2017-09-05 13:37:57